Vitamin A
What is Vitamin A?
Vitamin A is a fat-soluble vitamin that is essential for good health.
It is required for vision, growth, to fight infection, and for bone
remodeling. Two common types of vitamin A are retinol and beta carotene.
How can Vitamin A intake affect my bone health?
Recent studies in postmenopausal women showed that too much vitamin
A intake from retinol appeared to increase the risk
of hip fracture.
There is however conflicting evidence about the source of retinol associated
with an increased risk of hip fracture.There is no evidence of any
association between beta-carotene intake and the risk of osteoporosis
or related fracture. Beta-carotene is considered safe and is not associated
with any negative effects to bones or other parts of the body. Although
controlled studies are needed to further test these observations, it
makes sense to avoid too much retinol intake. It is however, important
to get enough vitamin A in your diet. You can do so by including generous
servings of foods high in beta carotene in your diet each day.
What foods contain retinol?
Retinol is found naturally in animal sources such as liver and fish
liver oils. In the past, cod liver oil, has been widely used as a source
of vitamin D but it is not currently recommended for that purpose.
Low levels of retinol are also added to many fortified foods such
as milk and fortified cereals. It is often listed on the food label
as vitamin A palmitate. The small amounts of retinol added to fortified
foods are not a concern if included in moderation in a healthy diet.
Are there other sources of retinol that I should know about?
Retinol is found in many multivitamins, vitamin A supplements, and
many combination vitamin A&D supplements. The supplement label
provides information about the type of vitamin A in the preparation
and how much vitamin A it contains. Retinol may be listed as retinyl
acetate, vitamin A palmitate, or vitamin A acetate. It is important
read the labels of multivitamins in order to select those that
contain higher levels of beta-carotene and lower levels of retinol.
In addition to dietary sources, oral synthetic retinoid medications
taken by some people to treat acne or other skin conditions have also
been shown to be detrimental to bone health particularly in children
and teens during the bone-building years. If you need to take these
medications, it is important to speak to your doctor about how to protect
your bones during treatment.
What is the best way to get vitamin A?
You can get all of the vitamin A that you need by consuming foods
rich in beta-carotene. Beta-carotene is found in plant foods, especially
in dark green leafy vegetables and deep yellow or orange fruits. For
information about the beta-carotene content of selected foods, check
on the USDA National Nutrient Database: listed
according to nutrient content or listed
alphabetically.
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